Biocompatible materials have received a great interest for different biomedical applications. The attributes of the ideal biocompatible material would include the ability to support cell growth either in vitro or in vivo, the ability to support the growth of a wide variety of cell types or lineages, the ability to be endowed with varying degrees of flexibility or rigidity required, the ability to have varying degrees of biodegradability, the ability to be introduced into the intended site in vivo without provoking adverse events, and the ability to serve as a vehicle or reservoir for delivery of cells, drugs or bioactive substances to the desired site of action.
For this purpose, polysaccharides were shown to be the materials of choice due to their validated biological properties. Indeed, many studies are currently drawn to materials obtained by ionotropic gelation (ability of polysaccharides such as pectin, alginate, carrageenan and gellan to form a gel in the presence of multivalent ions). However, those techniques are limited since they are carried out with a little range of polysaccharide type. In addition, those gels are not suitable for an easy and efficient administration within a human or animal tissue, independently of the size and localization of the target tissue. Lee C S et al. have illustrated the use of calcium-alginate beads also for tissue engineering of bone (Lee C S et al, Regulating in vivo calcification of alginate microbeads, Biomaterials 2010, June; 31(18):4926-34). Others have prepared polysaccharide beads from chitosan based polyelectrolytes for drug delivery systems. Further, chitosan based polyelectrolyte complexes were proposed as potential carrier materials in drug delivery systems (Hamman J H et al., Chitosan based polyelectrolyte complexes as potential carrier materials in drug delivery systems, J Biomed Mater Res, 2010).
However, the above mentioned polysaccharide beads are not adapted because of the instability of the divalent cations complexes under physiological conditions, and to the little range of potential polysaccharides to be used. In addition, the biocompatible materials currently used can not be easily administrated within a human or animal tissue, independently of the size and localization of the target tissue.
There is thus still a need for a biocompatible material adapted for an injection within the human or animal body and that can be used for biological and therapeutic purposes. Particularly, there is a need for a biocompatible material which would be easily administrated by injection to the human or animal tissue, independently of the site of action and of the size of the targeted region.